292 SUMMARY OF CURRENT RESEARCHES RELATING TO 



New Fermenting Fungus.* — E. C. Hansen describes a mould- 

 fungus found on cow-dung, and in fissures of sweet juicy fruits, 

 resembling a MonlUa, which produces active higher fermentation in 

 Baccliarine solutions, forming cells altogether similar to those of 

 Saccharomyrcs cerevisice. The fermentation caused by it differs, how- 

 ever, from that produced by all other ferments known at present, in 

 that it is wanting in the chemically soluble ferment invertin, and 

 consequently that it can ferment saccharose as such. 



Pilobolidae.t — W. B. Grove gives a detailed account of the 

 various points in the structure of this family of Mucorini, which he 

 divides into the two genera Pilobohis and Van Tieghem's Pilaira, 

 distinguished by the sporangiophore not being separated from the 

 mycelium by a septum, and the sporangium not being projected. Of 

 the former genus he enumerates and describes seven species as at 

 present known, of the latter three, including one new one. With 

 regard to the genetic relationships of the family, the author considers 

 that the known species form a close series which clusters round two 

 points, Piloholus Kleinii and Pilaira Cesaiii. He supposes the 

 family to have sprung from a species of Mucor, like M. plasmaticus, 

 which possesses abundance of interstitial gelatinous substance in 

 its sporangium, and which became provided with an upper indurated 

 cap, and a lower diffluent zone ; the sporangium, with its spores, 

 being thus enabled to drop off its stem, Pilaira would thus be a 

 stage in the evolution of Piloholus, in which a septum is formed at 

 the base of the si)orangioj)horc, and the rapid swelling of the lower 

 part would cause the well-known projection of the sporangium. 

 Piloholus longipes must be regarded as the highest type to which the 

 evolution of the Mucorini has yet advanced in this direction. 



Tetramyxa parasitica. J — K. Goebel finds peculiar tuberous struc- 

 tures on the stem, rachis, and leaves of Ruppia rostellata, of a yellowish 

 green or white colour, changing to brown in the autumn. They are 

 of parenchymatous structure, with a large dark brown central, and a 

 sharply differentiated cortical portion, the latter appearing white 

 from empty intercellular spaces. In the cells of the inner portion 

 were numerous spores, connected together in fours, with smooth 

 colourless membrane, coloured blue neither by sulphuric acid and 

 iodine, nor by chloriodide of zinc. 



In younger stages a plasmodium could be detected in the central 

 cells of these tubers, and in the plasmodium a number of small 

 nuclei, and sometimes also in the peripheral cells ; but these latter 

 were replaced afterwards by large starch-grains. On contact with 

 water the plasmodia contracted into spherical balls ; currents were 

 not observed in them. The formation of spores was preceded by 



• "Vers. Deutsch. Naturf. u. Aerzte Magdeburg, Sept. 19th, 1884. See Bot. 

 Centralbl, xx. (1884) p. 56. 



t Midland Naturalist, vii. (1884) pp. 131-5, 149-53, 184-7, 214-20, 253-60, 

 280-4. 304-9, 333-9 (2 pis.). 



J Flora, Ixvii. (1884) pp. 517-21 (1 pi.). 



